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(No Model.) 2 Sheets-Sheet 1.

C. L. CLARKE.

ELECTRIC CLOCK SYSTEM.

No. 347,572. Patented Aug. 17, 1886.

(No Model.) 2 Sheets-Sheet 2.

G. L. CLARKE.

ELECTRIC GLOGK SYSTEM.

No. 347,572. Patented Aug. 17,1886.

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SPECFICATION forming part of Letters Patent No. S11-"7,572, dated .August 1'?, 1886.

Application iled May 2l, lSSG,

Serial No. 02,834. (No model.)

To all 1071/0777J it may con/cern:

Be it known that il, CrmnLns L. Ummm, a citizen of the United States, residing in East Grange, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Electric Clock Systems, of which. the l'ollowingis a specification.

My invention relates to the construction of the class of devices controlled by electric currents transmitted from more or less distant points `for the purpose of indicating time.

rlhe object of the invention is to provide convenient, simple, and efficient means for causing the successive impulses to advance the clock-movements the required distance to insure that there shall be no excess of movement, and that the movement shall be as perfectly locked as possible at all times, and to maintain the circuits and circuit-connections in proper condition.

In carrying out the invention, the clockmovements arc constructed in essentially the following manner: An electro-magnet designed to be included in the main-line circuit is provided with an armature carried upon a lever having two pawls respectively designed to engage at different times the teeth of the main driving-wheel of the movement. A double loeking-pawl is applied to the wheel, and this is constructed in such manner that when one pawl is in engagementwith the Wheel the other is at the apex of one ot' the teeth, and vice versa. Vi-hcse two pawls are supported from the same pivot, and as one is being lifted from engagement with the wheel the other is entering the space between the two succeeding teeth. @ne pawl extends at right angles across the end ofthe other,1"or the purpose of bringingit into position to engage the wheel. Vhen a large number of clocks are included in series in a single circuit, it is desirable that some means should be employed for insuring that all have been actuated before the connections of the driving circuit are interrupted. For this purpose an organization ot' circuits somewhat similar te that described in my Patents os. 327,526 and 327,527 is employed. 'ilwo main lines are employed, one being designed to convey the currents lloractuating the moven'lents, and the other for operating a circuit interrupting device. iVhcn its connections are completed bythe operation et all the movements, both circuits are supplied from the same battery, and, as it is desirable that the resistance ofthe two should be approximately equal whatever number of clocks are included in circuit, and, as the number is liable to be variable, cach secondary movement is supplied with an artificial rcsistance which is approximately equal to that of the actuating magnet. 1Whatever resistance is then added to oncline by au additional actuating-magnet will be compensated in the other line by an artificial resistance.

In the accompanying drawings, Figure l is a front elevation. Fig. 2 is a plan, partly in section; and Fig. 3, a diagram illustrating the organization ol' a system.

Referring to the iicures, A represents a supporting-plate upon which several parts of the instrument are carried. An electro-magnet, B, acting upon an armature, o, is employed for operating a lever, C. The lever C is constructed with two arms, c/ and c", which respectively carry pawls d and di. The pawls are designed to engage the main wheel E of the clock-movement, anda spring, s, normally holds the lever in the position shown in the drawings, with the pawl d2 engaging the teeth of the wheel, the pawl d being out ot the path ofthe teeth and the armature I) away from its electro-magnet. When the magnet is vitalized, the armature is drawn forward, the pawl d strikes one of the teeth c near its apex, and by entering farther advances the wheel. Meanwhile the pawl d? is being withdrawn bctwcen two teeth, c2 c, thus permitting the forward movement of the wheel. When the pawl d has completed its forward movement, the tooth e will have advanced a suilicient distance to be engaged upon the opposite face by the pawl dL when the lever returns to its normal position, thus completing the advancement of the wheel E distance corresponding to one tooth.

For the purpose of preventing any retrograde movement of the wheel during the time thepawlsare out oi' engagement, two retaining pawls or dogs, j" and fl, are employed. The

former, which extends around the end of the IOO with the point.

latter of these, is in engagement withthe wheel, falling to the base of two of the teeth when the wheel is at rest, while the latter is at that moment upon the apex or crown of the succeeding tooth. The advancement caused by the pawl d will allow the pawl f2 to pass between two succeeding teeth. At the same time the pawl d will be gradually raised from the position shown in the drawings. The faces of the pawls are formed at such angles that they permit a forwardv movement of the wheel E, although preventing a backward movement of the same.

As it is desirable that the electro-magnet Bv should be shunted for the purpose of preventing it from sending to the main line a strong discharge-current when it becomes demagnetized, a permanent shunt-circuit of high resistance is closed around its coils by means of a conductor, l, including an artificial resistance, r.

The currents required for operating the several clocks which are included in a main line, L', (see Fig. 3,) are derived from a battery,0, which is in thisinstance located near the transmitting apparatus. One pole of this battery is connected with the earth at G by a conductor, 2, while the other pole is connected through a circuit-interrupting device and by a conductor, 5, with a contact-point, r2, constituting a lportion of any suitable form of circuit-closing device. An arm, r', applied to any moving part-say the second-hand arbor of the master-clock-is carried forward by the movements of the second hand arbor and makes sliding contact once each minute or at any other predetermined interval with the contact-point r2. rIhe point r2 is so placed that a single beat of the pendulum orasingle continuous movement of the second-hand arbor will carry the arm into and out of contact The arm a" is connected bya conductor, 3, through the coils of an electro! magnet, H, with the main line L, including the actuating-magnets of the several clocks. It is designed that for the momentary connection formed by the sweep of the arm 1" a continuous connection shall be substituted for the main line L', which will continue until the eircuit is interrupted at some other point. For this purpose the armature n of the electromagnct H is connected with the arm r', and a front y contact-point, n, applied thereto, is connected by conductor 4 with the conductor 5, leading to the point r2. rllhe vitalization of the electro-magnet H thus causes a circuit to be completed independently of the arm r and point r2.

The circuit-interrupting device consists of an electro -magnet, Q, included in a second main line, L2, branching from the conductor 5. This electro-magnet is provided with an armature, q', which when drawn forwardV strikes against one arm of a lever, q2, the opposite arm of which normally rests against the contact-point g3. The point g3 is connected with a battery, O, and the conductor 5 leads from the lever q2. When the armature q is actuated, the lever g2 is thrown out of contact `with the point q, thereby interrupting the connections of the battery through both lines. The connections of the line L2, however, are not completed until all the clocks have been actuated, for the reason that the line leads to the armature-lever of the first clock of the series, while the contact-point h2, applied to the lever, is connected with' the lever of the succeeding clock, and so onthroughout the series. In this manner the circuit is completed only when all the levers rest against their re spective contact-points h2.

It will be evident that each clock which is added to the system will introduce a resistance in the main line L, and unless some means are provided for equalizing the resistance of the line L2 the resistance of the line L would ultimately so far exceed that of the line L2 as to cause the current to be immediately diverted from the line L the moment the connections of the line L2 are completed, thus causing the electro-magnet H to be demagnetized too quickly. To avoid this, a resistance, R, is included between each lever, C, and the conductor leading thereto from the correspond ing section of the main line L2, which is approximately equal to the resistance of the corresponding actuating-magnet B.

I claim as my invention- 1. rIhe combination, with an electro-magnet and a clock-movement, of a lever actuated by the magnet, two pawls carried by said lever and engaging the teeth of one of the wheels of said movement, two independent retaining pawls resting upon the teeth of said wheel and respectively engaging the teeth at different points in its movement, substantially asdescribed, and a circuit-closing device consisting of said lever and the limiting-stop applied thereto. s

2. In an electric clock-movement, the combination of an actuating-magnet, a lever controlled thereby and having two arms extending upon the opposite sides of a wheel of said movement, two drivingpawls respectively carried upon said arms, two retaining-pawls respectively engaging the teeth of said wheel at different points in its revolution, said pawls being supported in the Same axial line and one of them extending across the end of the other.

8. IIhe combination of a series of electromagnets, devices actuated thereby, a main line including the same, means for completing a circuit through said main line, a second main line having its connections completed by the operation of all of said devices, an articial resistance included i-n said second main line at each of said devices, and a circuit-interrupting device actuated by a current through said second main line.

4. The combination of a battery, #two main lines deriving currents therefrom, a series of IIO electricallynctuated devices having` their act- In testimony whereof I have hereunto subuuting-nmgnets included in one of said 11min scribed my nume this 12th day of May, A. D. lines, u cireuit-interrupting device for said 1886. main line having its actuating-magnet inelud- 5 ed in the second of said main lines, menus for CHAS. L. CLARKE.

*completing the circuit of the second line when all of Suid devices have been actuated, and un W-itnesses: artificial resistance included in the circuit ol" GARONNE E. DAVIDSON, the second line at each of said devices, suh- CHARLES A. TERRY.

1o stantiully ns describcrh 

